The present invention relates to a device for positioning optical fibers in a terminal connector intended for splicing two optical-fiber transmission cables each comprising, under a protection sheath, a dielectric cylindrical support reinforced along its axis and comprising grooves, either longitudinal or helical, disposed evenly over its periphery and in each of which is housed an optical fiber.
Methods and devices are already known for connecting or splicing such optical-fiber transmission cables. Reference may be made for example to the French Patent No. 2,420,777 filed by the present Assignee on Mar. 24, 1978 for "Method and apparatus for splicing optical-fiber cables". According to this patent, the method of splicing two optical-fiber transmission cables comprises the following steps carried out at each end of cable:
the ends of the cables are stripped over a predetermined length;
the fibers thus freed are opened outwardly and are temporarily fixed on a support surrounding the cable;
the support, freed of its fibers, is cut perpendicularly to its axis and a terminal connector is rigidly fixed thereto, comprising grooves disposed evenly over its periphery, and having the same angular spacing as the grooves of the support of said cable;
the fibers are brought down into the grooves of this connector and they are rigidly fixed therein;
this connector as well as the fibers which it carries are cut perpendicularly to its axis and said connector is polished;
each of the support-connector assemblies is permanently fixed with rigidifying means;
the two cut faces are placed in contact and the two cables are aligned with aligning means; and
the two cut faces are pressed together by appropriate clamping means.
However, the operation of the above-described method consisting in bringing down the fibers, for example by means of pincers, more particularly of the tweezer type, into the grooves of the terminal connector, presents disadvantages. In fact, this operation is carried out manually, so making use of the dexterity of the operator. Thus, it may happen through clumsiness that two optical fibers are positioned in the same groove of the terminal connector. Consequently, perfect execution of this operation of positioning an optical fiber in each groove of the connector cannot be guaranteed. Furthermore, this operation may require a relatively large force to be exerted on the optical fiber in order to position it in a groove, which may even cause said fiber to break. Moreover, this operation takes a relatively long time to carry out, which appreciably increases the time for splicing, particularly in situ, two optical-fiber transmission cables.
The aim of the present invention is to overcome these disadvantages by providing a mechanical device for positioning optical fibers in grooves of the terminal connector for splicing two optical-fiber transmission cables of the above-described type, which is entirely satisfactory, simple in structure, reliable and ensures rapid and strict positioning of a single optical fiber per groove, thus eliminating the human factors.
To this end, the object of the invention is a device for positioning optical fibers in grooves formed in the periphery of a terminal connector intended for splicing two optical-fiber transmission cables, comprising:
an optical-fiber insertion piece comprising a central recess provided substantially over all its length and radial slits provided in the periphery of the insertion piece and extending substantially over all the length of this insertion piece, the terminal connector being fitted into the central recess so that each of its grooves is disposed opposite a slit in the insertion piece; and
optical-fiber distribution means mounted freely rotatable on the insertion piece and having an additional longitudinal slit intended to come successively opposite each slit of the insertion piece, the optical fibers being presented one by one to the additional slit of the distribution means so that, through rotation of the distribution means, each optical fiber penetrates into a groove of the terminal connector through the slit of the distribution means located opposite a slit in the insertion piece.
According to another feature of the invention, the distribution means comprise a ring mounted in abutment on one end of the insertion piece, the optical fibers being disposed bearing on the outer periphery of the ring.
It will be readily understood that thus, once the end of the cable has been stripped over a predetermined length, the optical fibers thus freed will come and open out around the ring which will successively present, by rotation, each slit to each optical fiber, so that said fiber will pass down into a slit of the insertion piece and will be easily positioned in a groove of the terminal connector. Thus, this rotating ring for distributing optical fibers forms a simple and efficient means facilitating more especially the operation of positioning each optical fiber in a groove of the terminal connector.